From 315bcfeee0a438e687529435a68ea6e809950a45 Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Wed, 31 Dec 2025 15:48:44 -0500
Subject: [PATCH] Fixed JSONB path_match and path_exists operators to use
 correct type coercion

Fixed issue where PostgreSQL JSONB operators
:meth:`_postgresql.JSONB.Comparator.path_match` and
:meth:`_postgresql.JSONB.Comparator.path_exists` were applying incorrect
``VARCHAR`` casts to the right-hand side operand when used with newer
PostgreSQL drivers such as psycopg. The operators now indicate the
right-hand type as ``JSONPATH``, which currently results in no casting
taking place, but is also compatible with explicit casts if the
implementation were require it at a later point.

Fixes: #13059
Change-Id: I8e1a58361456f7efabf4940339cb5ce2c5a1d5f9
(cherry picked from commit a88f89849e303ab441082de788545ee8a698dc2e)
---
 doc/build/changelog/unreleased_20/13059.rst | 14 +++++++
 lib/sqlalchemy/dialects/postgresql/json.py  |  9 +++++
 test/dialect/postgresql/test_types.py       | 44 +++++++++++++++++++++
 3 files changed, 67 insertions(+)
 create mode 100644 doc/build/changelog/unreleased_20/13059.rst

diff --git a/doc/build/changelog/unreleased_20/13059.rst b/doc/build/changelog/unreleased_20/13059.rst
new file mode 100644
index 0000000000..caeca4a7c3
--- /dev/null
+++ b/doc/build/changelog/unreleased_20/13059.rst
@@ -0,0 +1,14 @@
+.. change::
+    :tags: bug, postgresql
+    :tickets: 13059
+
+    Fixed issue where PostgreSQL JSONB operators
+    :meth:`_postgresql.JSONB.Comparator.path_match` and
+    :meth:`_postgresql.JSONB.Comparator.path_exists` were applying incorrect
+    ``VARCHAR`` casts to the right-hand side operand when used with newer
+    PostgreSQL drivers such as psycopg. The operators now indicate the
+    right-hand type as ``JSONPATH``, which currently results in no casting
+    taking place, but is also compatible with explicit casts if the
+    implementation were require it at a later point.
+
+
diff --git a/lib/sqlalchemy/dialects/postgresql/json.py b/lib/sqlalchemy/dialects/postgresql/json.py
index fec711e62d..5baa41df7c 100644
--- a/lib/sqlalchemy/dialects/postgresql/json.py
+++ b/lib/sqlalchemy/dialects/postgresql/json.py
@@ -33,6 +33,7 @@ from ...sql._typing import _T
 if TYPE_CHECKING:
     from ...engine.interfaces import Dialect
     from ...sql.elements import ColumnElement
+    from ...sql.operators import OperatorType
     from ...sql.type_api import _BindProcessorType
     from ...sql.type_api import _LiteralProcessorType
     from ...sql.type_api import TypeEngine
@@ -311,6 +312,14 @@ class JSONB(JSON):
 
     __visit_name__ = "JSONB"
 
+    def coerce_compared_value(
+        self, op: Optional[OperatorType], value: Any
+    ) -> TypeEngine[Any]:
+        if op in (PATH_MATCH, PATH_EXISTS):
+            return JSON.JSONPathType()
+        else:
+            return super().coerce_compared_value(op, value)
+
     class Comparator(JSON.Comparator[_T]):
         """Define comparison operations for :class:`_types.JSON`."""
 
diff --git a/test/dialect/postgresql/test_types.py b/test/dialect/postgresql/test_types.py
index acd3b1f2c5..88324196dc 100644
--- a/test/dialect/postgresql/test_types.py
+++ b/test/dialect/postgresql/test_types.py
@@ -6561,6 +6561,50 @@ class JSONBRoundTripTest(JSONRoundTripTest):
         res = connection.scalar(q)
         eq_(res, {"k1": {"r6v1": {"subr": [1, 3]}}})
 
+    @testing.only_on("postgresql >= 12")
+    def test_path_exists(self, connection):
+        self._fixture_data(connection)
+
+        q = select(self.data_table.c.name).where(
+            self.data_table.c.data.path_exists("$.k1")
+        )
+        res = connection.scalars(q).all()
+        eq_(set(res), {"r1", "r2", "r3", "r4", "r5", "r6"})
+
+        q = select(self.data_table.c.name).where(
+            self.data_table.c.data.path_exists("$.k3")
+        )
+        res = connection.scalars(q).all()
+        eq_(res, ["r5"])
+
+        q = select(self.data_table.c.name).where(
+            self.data_table.c.data.path_exists("$.k1.r6v1")
+        )
+        res = connection.scalars(q).all()
+        eq_(res, ["r6"])
+
+    @testing.only_on("postgresql >= 12")
+    def test_path_match(self, connection):
+        self._fixture_data(connection)
+
+        q = select(self.data_table.c.name).where(
+            self.data_table.c.data.path_match("$.k3 > 0")
+        )
+        res = connection.scalars(q).all()
+        eq_(res, ["r5"])
+
+        q = select(self.data_table.c.name).where(
+            self.data_table.c.data.path_match("$.k3 == 5")
+        )
+        res = connection.scalars(q).all()
+        eq_(res, ["r5"])
+
+        q = select(self.data_table.c.name).where(
+            self.data_table.c.data.path_match('$.k1 == "r1v1"')
+        )
+        res = connection.scalars(q).all()
+        eq_(res, ["r1"])
+
 
 class JSONBSuiteTest(suite.JSONTest):
     __requires__ = ("postgresql_jsonb",)
-- 
2.47.3